The present invention relates to a shift lever apparatus, and more particularly, to a shift lever apparatus which is provided in a vehicle with an automatic transmission and which includes a locking mechanism for the shift lever and a key-interlock mechanism which operates in conjunction with the locking mechanism.
A shift lever apparatus has been disclosed in the Japanese Patent Application Laid Open No. 60-135352. In this shift lever apparatus, as shown in FIG. 1, a base portion 1a of a shift lever 1 is pivotally supported on a machine casing 7 and a positioning pin 2 is arranged on the shift lever 1 so as to freely move upwards and downwards. The positioning pin 2 is energized upwards by energizing means (not shown) at all times and can be moved downwards when a knob button (not shown) provided on the upper part of the shift lever 1 is pressed. A bell-crank 4 with an engaging slot 4a is pivotally supported on a positioning plate 3 and is energized by a spring 8 at all times so as to rotate clockwise. The engaging slot 4a of the bell-crank 4 engages with the positioning pin 2 when the positioning pin 2 is at the parking position (P) of an opening 3a formed in the positioning plate 3. Further, a key-lock-cable 6 which operates in conjunction with a key-interlock mechanism (not shown) is connected to the bell-crank 4.
When the above-described shift lever apparatus is in a steering-lock state in which the engine key is removed from the key-interlock mechanism, if a user tries, pressing the knob button, to move the positioning pin 2 downwards so that the positioning pin 2 moves from the parking position (P) toward a running position, the bell-crank 4 rotates clockwise. Consequently, a feeding force acts upon the key-lock-cable 6, thereby causing the cable 6 to stretch. Further, in the worst situation, there is concern that a lock in the key-interlock mechanism may be released.
Moreover, the slot width of the engaging slot 4a of the bell-crank 4 is set larger than the diameter of the positioning pin 2 so as to freely move the positioning pin 2 upwards and downwards. Consequently, the play generated between the positioning pin 2 and the engaging slot 4a results in play being generated when the key-lock-cable 6 is pushed or pulled by the bell-crank 4, thereby causing the function of the key-interlock mechanism to deteriorate.
Furthermore, the spring 8 is necessary to produce tension in the key-lock-cable 6 in the direction shown by the arrows in FIG. 1, whereby the positioning pin 2 and the bell-crank 4, respectively, are energized in substantially opposite directions. In this way, the upward energizing force on the positioning pin 2 must be set larger than the clockwise energizing force on the bell-crank 4 to produce tension in the key-lock-cable 6. Accordingly, the force to operate or press the knob button has to be relatively large, thereby resulting in poor operating characteristics in the shift lever 1.